Singlet oxygen attack on rubbers and poly(olefins) is likely to be significant in the presence of sensitizing impurities such as oxidation products, polynuclear aromatic pollutants, and many additives. 1O2 attack will yield hydroperoxide groups, and so markedly impair the subsequent heat and light stability of the materials. However stabilizer systems which have already been developed can be expected to protect against the effects of 1O2 by quenching to the relatively inoccuous 2O3 (ground state oxygen). For rubbers the aromatic amines widely employed as antizonants will protect against 1O2 attack, whereas the nickel chelates employed as uv stabilizers will protect poly(olefins).